8 ms·

Mimicking an impact on Earth’s early atmosphere yields all 4 RNA bases

230 points by curtis 10y ago

Blinks- 10y ago
When I was in middle school I read a new book about cell structure I found in the library, my favorite chapter was always about the so called primordial soup of lipids and simple organic compounds that could have setup the chemical basis for polymers to form and in turn create the building blocks for RNA. It was one of the main things that gave me an interest in science and engineering, up until that point people had always given me a "god did it" or "we still have no theories on that son". This brings me back to the good ol' days of trying to explain how RNA could come about, as a 12 year old, to middle aged religious teachers who shot me down every time. As a kid this made me turn to outside sources for knowledge, and in retrospect that was actually a good thing.
- civilian 10y ago
  You might enjoy "The Vital Question", it dives deeper into abiogenesis and gives a really good theory. (Hint: why rely on meteors when alkaline deep-sea vents solve the energetic needs of a proto-life?) Here is Bill Gates' review of it: https://www.gatesnotes.com/Books/The-Vital-Question https://www.gatesnotes.com/Books/The-Vital-Question
- jacquesm 10y ago
  12 to 15 is roughly the time when as a child you realize adults are just big kids and are wrong as often as they're right. It's hard to get back to some level of respect after that, it's a bit like finding out Santa does not exist.
  - Arizhel 10y ago
    I'm over 40 now. I realized what you're saying to an extent, but for a long time I assumed that older adults would have the benefit of wisdom, life experience, maturity, etc. As I've aged, I've been consistently disappointed. I now believe differences in how people behave, according to age, are really a product of generational differences, and that people really don't change very much after they pass 30.
mtdewcmu 10y ago
The hypothesis that goes something like RNA bases -> RNA -> proteins -> life seems to sidestep the issue of metabolism, i.e. what did the first organism eat? What was its energy source? When I picture life arising from nothing, the most plausible scenario seems to involve increasingly intricate chemical reactions that initially do absolutely nothing other than create longer and longer staircases for energy to step through through before dissipating and becoming useless. In other words, you start with metabolism first, and then get structure later. It seems plausible that the earliest proto-metabolisms didn't use RNA or resemble modern life in any way. There might have been a succession of proto-metabolisms before getting to anything we would recognize as life. They would likely not have left any fossil record. Does this make any sense to anybody?
- kornish 10y ago
  You may be interested in this article, which espouses a similar idea that life is a mechanism for more efficiently dissipating energy, and thus a natural consequence of a universe following the Second Law of Thermodynamics: https://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/ https://www.quantamagazine.org/20140122-a-new-physics-theory... (disclaimer: the article is quite handwavy, but could be a good jumping-off point if you so choose. Sounds dubious to me but interesting to consider)
  - mtdewcmu 10y ago
    Life seems like a very inefficient way to dissipate energy. And that's kind of the point, you need to hang onto the energy long enough to do something with it before it dissipates. The most efficient way of dissipating energy seems like it would be something like Photon comes in -> photon reflects off water -> photon goes back out to space
    - justinator 10y ago
      Life is pretty good at entropy. Take for example: humans. We've been digging up vast amounts of fossil fuels to then burn them up. Without us, those reserves would stay in the ground probably forever. Is there another organism that's better entropy as us? (actually I think there are contenders) Perhaps that's our reason for being.
apo 10y ago
This type of research is mostly a dead end. Abiotic processes for generating amino acids and nucleotides from smaller components are well-known. The mystery revolves around how these building blocks turn into life through abiotic processes. We really haven't got a clue. As a chemist, I view this as the most important unsolved problem the discipline has to offer. Solving this mystery would likely be the most significant turning point in human history. This reminds me of something Paul Graham once said. Knowing a problem exists isn't sufficient justification to solve it. You also need an approach. The approach to solving the origin of life problem does not exist (yet).
- theoh 10y ago
  I'm not sure what Graham meant by "justification", if indeed that's the word he used. That would be a "why" not a "how". Of course you need an attack to solve a problem. Just formulating the problem doesn't guarantee a solution. There must be more to what Graham said than what you are reporting.
- gnaritas 10y ago
  > Solving this mystery would likely be the most significant turning point in human history. I can't imagine how; most people will simply dismiss it and continue praying to their Gods and scientists already believe what it would prove so few minds would change and unless it directly leads to some practical output it simply won't matter to most of the world.
  - apo 10y ago
    With understanding of a process comes the possibility (or inevitability) of controlling it. I'm not referring to mythology, but rather technology.
    - gnaritas 10y ago
      Which is what I was referring to by some practical output; however it's possible and common to acquire knowledge without there being immediate things to do with it. Certainly the knowledge is progress, but you called it the most significant in human history, that's a bold claim, care to expand on how so?
deepnet 10y ago
67P Churyumov-Gerisimenko is a very dirty snowball. Comets may have brought much of Earth's water. Ice, dust & tholins. Tholins are a sort of like a simple crude oil, thick tarry and orangy brown - very rich in primitive organics and amino acid precursors. Pluto is red with tholins. http://www.planetary.org/blogs/guest-blogs/2015/0722-what-in-the-worlds-are-tholins.html http://www.planetary.org/blogs/guest-blogs/2015/0722-what-in...
aristus 10y ago
In the 1950s they discovered that sending high current through a (sterile) organic watery soup would generate a dozen or so kinds of amino acids. The hypothesis was that tens of millions of years of lightning strikes on the ocean could in theory get the party started.
- SomewhatLikely 10y ago
  That experiment is literally described in the first paragraph of TFA.

230 points by curtis 10y ago

When I was in middle school I read a new book about cell structure I found in the library, my favorite chapter was always about the so called primordial soup of lipids and simple organic compounds that could have setup the chemical basis for polymers to form and in turn create the building blocks for RNA. It was one of the main things that gave me an interest in science and engineering, up until that point people had always given me a "god did it" or "we still have no theories on that son". This brings me back to the good ol' days of trying to explain how RNA could come about, as a 12 year old, to middle aged religious teachers who shot me down every time. As a kid this made me turn to outside sources for knowledge, and in retrospect that was actually a good thing.

civilian 10y ago
You might enjoy "The Vital Question", it dives deeper into abiogenesis and gives a really good theory. (Hint: why rely on meteors when alkaline deep-sea vents solve the energetic needs of a proto-life?) Here is Bill Gates' review of it: https://www.gatesnotes.com/Books/The-Vital-Question https://www.gatesnotes.com/Books/The-Vital-Question
jacquesm 10y ago
12 to 15 is roughly the time when as a child you realize adults are just big kids and are wrong as often as they're right. It's hard to get back to some level of respect after that, it's a bit like finding out Santa does not exist.
- Arizhel 10y ago
  I'm over 40 now. I realized what you're saying to an extent, but for a long time I assumed that older adults would have the benefit of wisdom, life experience, maturity, etc. As I've aged, I've been consistently disappointed. I now believe differences in how people behave, according to age, are really a product of generational differences, and that people really don't change very much after they pass 30.

mtdewcmu 10y ago

The hypothesis that goes something like RNA bases -> RNA -> proteins -> life seems to sidestep the issue of metabolism, i.e. what did the first organism eat? What was its energy source? When I picture life arising from nothing, the most plausible scenario seems to involve increasingly intricate chemical reactions that initially do absolutely nothing other than create longer and longer staircases for energy to step through through before dissipating and becoming useless. In other words, you start with metabolism first, and then get structure later. It seems plausible that the earliest proto-metabolisms didn't use RNA or resemble modern life in any way. There might have been a succession of proto-metabolisms before getting to anything we would recognize as life. They would likely not have left any fossil record. Does this make any sense to anybody?

kornish 10y ago
You may be interested in this article, which espouses a similar idea that life is a mechanism for more efficiently dissipating energy, and thus a natural consequence of a universe following the Second Law of Thermodynamics: https://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/ https://www.quantamagazine.org/20140122-a-new-physics-theory... (disclaimer: the article is quite handwavy, but could be a good jumping-off point if you so choose. Sounds dubious to me but interesting to consider)
- mtdewcmu 10y ago
  Life seems like a very inefficient way to dissipate energy. And that's kind of the point, you need to hang onto the energy long enough to do something with it before it dissipates. The most efficient way of dissipating energy seems like it would be something like Photon comes in -> photon reflects off water -> photon goes back out to space
  - justinator 10y ago
    Life is pretty good at entropy. Take for example: humans. We've been digging up vast amounts of fossil fuels to then burn them up. Without us, those reserves would stay in the ground probably forever. Is there another organism that's better entropy as us? (actually I think there are contenders) Perhaps that's our reason for being.

apo 10y ago

This type of research is mostly a dead end. Abiotic processes for generating amino acids and nucleotides from smaller components are well-known. The mystery revolves around how these building blocks turn into life through abiotic processes. We really haven't got a clue. As a chemist, I view this as the most important unsolved problem the discipline has to offer. Solving this mystery would likely be the most significant turning point in human history. This reminds me of something Paul Graham once said. Knowing a problem exists isn't sufficient justification to solve it. You also need an approach. The approach to solving the origin of life problem does not exist (yet).

theoh 10y ago
I'm not sure what Graham meant by "justification", if indeed that's the word he used. That would be a "why" not a "how". Of course you need an attack to solve a problem. Just formulating the problem doesn't guarantee a solution. There must be more to what Graham said than what you are reporting.
gnaritas 10y ago
> Solving this mystery would likely be the most significant turning point in human history. I can't imagine how; most people will simply dismiss it and continue praying to their Gods and scientists already believe what it would prove so few minds would change and unless it directly leads to some practical output it simply won't matter to most of the world.
- apo 10y ago
  With understanding of a process comes the possibility (or inevitability) of controlling it. I'm not referring to mythology, but rather technology.
  - gnaritas 10y ago
    Which is what I was referring to by some practical output; however it's possible and common to acquire knowledge without there being immediate things to do with it. Certainly the knowledge is progress, but you called it the most significant in human history, that's a bold claim, care to expand on how so?

deepnet 10y ago

67P Churyumov-Gerisimenko is a very dirty snowball. Comets may have brought much of Earth's water. Ice, dust & tholins. Tholins are a sort of like a simple crude oil, thick tarry and orangy brown - very rich in primitive organics and amino acid precursors. Pluto is red with tholins. http://www.planetary.org/blogs/guest-blogs/2015/0722-what-in-the-worlds-are-tholins.html http://www.planetary.org/blogs/guest-blogs/2015/0722-what-in...

aristus 10y ago

In the 1950s they discovered that sending high current through a (sterile) organic watery soup would generate a dozen or so kinds of amino acids. The hypothesis was that tens of millions of years of lightning strikes on the ocean could in theory get the party started.

SomewhatLikely 10y ago
That experiment is literally described in the first paragraph of TFA.